text: Pharmacognosy, the investigation of botanics used in indigenous medical traditions is essentially classical pharmacology. Pharmacognosy and classical pharmacology are both often contrasted with reverse pharmacology, that is, working from the target backward to identify new drugs starting with screening libraries of compounds for affinity for particular target. In pharmacognosy, folk medicines are first tested in clinical trials for efficacy.  Only after efficacy has been established, is an effort made to determine the biologic target of the drug.